Electric-current governor.



No. 796,935. PATBNTED AUG. 8, 1905. H. K. SANDBLL. BLEGTRIG CURRENT GOVERNOR.

APPLICATION FILED DEO.21. 1904.

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UNITED STATES PATENT OFFICE.

Specification of Letters Patent.

Patented Aug. 8, 1905.

Application filed December 21, 1904. Serial No. 237,795.

the speed, and under increase of load to cut out such resistance for increasing the speed or maintaining the normal speed of rotation. This I accomplish by a construction of governor which will cause it to contract in rotating at abnormally high speed under the action of centrifugal force and in contracting v break electrical contact with a resistance-terminal in the circuit to be controlled, and. .thereby cut in such resistance to lower the speed of rotation, and which will expand in rotating at lower speed, with the effect of making electrical contact with the resistanceterminal, and thereby cut out the resistance to increase the speed of rotation.

The novel principle involved in my invention may be embodied in various constructions of governor; but the most desirable embodiment thereof now known to me is that illustrated in the accompanying drawings, in which Figure 1 is a view in the nature of a diagram, showing in plan my improved governor with the commutator broken, of an electric motor on a rotatable shaft and included in the resistance-coil-containing circuit of an electric generator; Fig. 2, a face view of the preferred form of governor of my invention;

Fig. 3, a view showing by way of diagram the end of the sectional expansible and contractible contact-hub of the governor in its position relative to the brushes forming the resistance-coil terminals presented in edge or side elevation, and Fig. 4 a section taken at the line 4 on Fig. 2 and viewed in the direction of the arrow.

A is the governor, shown in its preferred general disk shape and formed, by preference, entirely of metal, brass being the material I have employed. The disk from which the body of the device is formed is cut away at opposite sides of its center, producing the openings (0 and Z) in said sides and leaving the central diametrical bar 0 with arc-shaped re:

silient arms (Z and 6 extending correspondingly in direction from its ends and terminating, respectively, inthe free circular heads d and e. A link f is pivoted at one end to the head d and contains an elongated slot f near its opposite, end, this link crossing and lying against the bar 0, with its end at the 'side of the center of the bar adjacent to the opening Z), where it is movably held by a pin f extending from the face of the bar through said slot, and a similar link g is pivoted at one end to the head 6 and contains an elongated slot 9' near its opposite end, the link 9 crossing and lying against the face of the bar 0, with its end at the side of the center of the bar adjacent to the opening a, where it is movably held by a pin g extending from the face of the bar through the slot. The ends of the links, which are thus connected with the bar 0, are expanded and carry, respectively, theoutwardly-projecting sections it and/1., forming the divided metal head B, which is the contact-producing element of the governor.

From the foregoing description of the governor it will be apparent that in rotating about an axis corresponding with the center of the bar 0, which thus lies between the headsections it and h, the centrifugal force will expand the yielding arms d and 6 toward their free ends in contrary directions, with the ef fect, owing to the manner of link connection of those ends of the'arms with the head-sections, of forcing the latter toward each other, while reduction in the centrifugal force of the governor in rotating will, owing to the described link connections, tend to contract the arms (Z and 6 toward each other, with the effect of spreading apart the sections 71. it. These movements of the head-sections in the particular construction of thegovernor herein represented are employed to make and break electrical contact with one or more resistance-terminals in an electrical circuit, as and for the purpose described as follows, with reference to Fig. l:

C denotes an electric generator represented as a dynamo-electric machine.

1) denotes the commutator of an electric motor, (not shown,) the brush z' on which is connected by the wire w with one pole of the generator, the other pole thereof being connected with the commutator-brush a" by a wire w, containing a resistance-coil w. On the commutator-shaft D, which has 1ts bearing at D is secured the governor A at a metal sleeve 70, projecting from the center of the face thereof opposite that from which the contact members It and It extend and surrounding the shaft to which it is secured, as by a set screw Z, and a brush 71: is applied to the sleeve D, being connected by a branch wire 10 with the wire w. Three brushes m, n, and 0 are shown in series adjacent to the head B and are disposed in different planes, as indi-.

cated in Fig. 3, whereby the free end of the brush m. is nearest the surface of the head, that of the brush n. farther removed therefrom, and that of the brush 0 still farther removed, the normal variation in distance of separation when the governor isrotating at full speed and the brushes are all out of contact with the head being, say, about oneeighth of an inch, while about one thirty-second of an inch may be the distance of separation of the contact end of the brush m from the head B when the members lb and it are closest together. \Vires m, a, and 0 connect different sections of the coil 20 with the respective brushes m, a, and 0.

Fig. 2 shows the members 71/ and h of the governor at the limit of their possible extent of separation, which is their condition when the motor is at rest, wherein the one of said members which happens to be adjacent to the brushes m, n, and 0 will contact with all of them, so that when the motor starts up all of the resistance 0.0 will be cut out and the flow of current from the generator will be over the wires w and 0, brush 0, governor, brush 7/, wire w, brush el, commutatorbrush 2?, and wire '10 back to the generator. After starting the motor as it speeds up, the arms cl and a, controlling the governor, will distend by centrifugal force and move the members h it toward each other, thereby separatwill traverse the wire on. and brush m in its described course back to the generator, and further increase in the speed of rotation by increasingly spreading the arms (Z and 6 brings the governor-sections still closer together and separates the latter from the brush 922, thereby cutting in the remaining section of the coil 10 and causing the current from the generator to traverse the wire w through the entire resistance to the commutator in reaching the generator C. From this it will be seen that as the load on the motor increases, causing slowing down of the speed, the resultant reduction in centrifugal force induces contraction of the' arms (Z and e and attendant spreading apart of the governor members, with the effect of cutting out resistance and regulating the speed accordingly, and that reduction in the load is attended with regulation of the speed of rotation by the effect of the increased centrifugal force s 'ireading the arms (l and e, with attendant movement toward each other, of the governor members and resultant cutting in of the resistance.

The gist of my invention consists in providing in an electric-current governor relatively movable contact-controlling members to operate automatically by contraction under the action of centrifugal force to cut in and by expansion under reduction in the centrifugal force to cutout resistance in the circuit, and thereby, as one of different applications to which it is adapted, regulate the speed of rotation of an electric motor in the circuit, and it is not necessary to this end that the relatively movable members shall themselves be of conducting material or in cluded in the circuit, for they may be employed for otherwise making and breaking contact in the circuit to be controlled and may be variously constructed differently from the construction shown and described without departure from my invention.

\Nhat I claim as new, and desire to secure by Letters Patent, is

1. In combination with an electric circuit containing resistances having contact-terminals, a current-governor having a head formed of relatively separable and approachable contact making and breaking members actuated by variation in the speed of rotation of the governor to approach one another under increasing centrifugal force and thereby contract said head away from said terminals, and

r to separate and expand the head toward said terminals under decreasing centrifugal force, for the purpose set forth.

2. In combination with an electric circuit containing resistances having contact-terminals, a current-governor having a head formed of relatively separable and approachable metallic contact making and breaking members provided with rounded contact-surfaces and actuated by variation in the speed of rotation of the governor to approach one another under increasing centrifugal force and thereby contract said head away from said terminals, and to separate and expand the head toward said terminals under decreasing centrifugal force, for the purpose set forth.

3. In combination with an electric circuit containing resistances having contact-terminals, acurrent-governor having a head formed of relatively separable and approachable contact making and breaking members and arms connected therewith centrifugally expansible and centripetally contractible under variation in the speed of rotation and operating to separate and thereby expand the head against said terminals under decreasing centrifugal force and to contract the head by bringing said members toward' each other away from said terminals under increasing centrifugal force, for the purpose set forth.

4. In combination with an electric circuit containing resistances having contact-terminals, acurrent-governor having a head formed of relatively separable and approachable metallic contact making and breaking membersprovided with rounded surfaces and arms connected therewith centrifugally expansible and centripetally contractible under variation in the speed of rotation and operating to separate said members and thereby expand the head against said terminals under decreasing centrifugal force, and to contract the head by bringing said members toward each other away from said terminals under increasing centrifugal force, for the purpose set forth.

5. In combination with an electric circuit containing resistances having contact-terminals, a current-governor having a central metal head formed of relatively separable and approachable contact making and breaking members and resilient arms connected with said members actuated by variation in-the speed of rotation of the governor to move said members toward one another away from said terminals under increasing centrifugal force and from one another toward said terminals under decreasing centrifugal force, for the purpose set forth.

6. In combination with an electric circuit containing a motor and resistances having contact-terminals, a generally disk-shaped electrio-current governor on the motor-shaft, having a central head formed of relatively separable and approachable contact making and breaking members, and arms connected with said members actuated by variation in the speed of rotation of the governor to move said members toward one another away from said terminals under increasing centrifugal force and from one another toward said terminals under decreasing centrifugal force, for the purpose set forth.

7. In combination with an electric circuit containing resistances having contact-terminals, an electric-current governor. adapted to be secured on a rotatable shaft and com prising a bar having arms extending from its opposite ends, links extending from the free ends of said arms in relatively contrary directions across said bar near its center and movable thereon, and head-sections on said link ends, for the purpose set forth,

8. In combination with an electric circuit containing resistances having contact-terminals, a generally disk-shaped metal electriccurrent governor adapted to be secured on a rotatable shaft and comprising a bar having resilient arc-shaped arms extending from its opposite ends, links extending from the free ends of said arms in relatively contrary directions across said bar near its center and confinedly movable thereon, and head-sections on said link ends, for the purposeset forth.

HENRY K. SANDELL. In presence of L. HEISLAR, J. H. LAUDES. 

